Self-locking nut



A. A. BROWN. SELF LOCKING NUT.

No, 525,837. Patented Sept. 11, 1894.

NITED STATES PATENT FFICE.

ALFOARD A. BROl/VN, OF SAN FRANCISCO, ASSIGNOR, BY DIRECT AND MESNEASSIGNMENTS, OF ONE-HALF TO ORAMEL J. MUOHMORE AND DANIEL P. N. LITTLE,OF LOS ANGELES, CALIFORNIA.

SELF-LOCKING NUT.

SPECIFICATION forming part of Letters Patent No. 525,837, datedSeptember 11, 1894.

Application filed March 10, 1892.

To all whom it may concern.-

Bfeit known that I, ALFOARD ABEL BROWN, a citizen of the United States,residing at San Franclsco, in the county of San Francisco and 5 State ofCalifornia, have invented new and useful Improvements in Self-LockingNuts, of which the following is a specification.

My invention relates especially to those self-locking nuts consisting oftwo members provlded with oppositely arranged cam faces adapted toengage with each other to prevent the rotation of the membersindependent of each other. The great objection to devices of this kindheretofore has arisen from the r fact that in screwing the nut home uponthe bolt, there is great liability of splitting the washer by reason ofthe manner in which the force is applied to the ofisets upon the washer.This has necessitated the use of washers of considerable thickness toprevent splitting the washer and this thickness is objectionable formany reasons. The object of my invention is to provide an improved nutof this character in which both 2 5 members combined will be ofsubstantially no greater thickness than an ordinary nut and washer, andin which all liability of bursting the washer while screwing the nuthome upon the bolt is avoided. The accompanying drawings illustrate mylnvention. Figure 1 is a side view of one form of my lmproved nutapplied to a fish joint bolt in place upon its fish plate and rail. Fig.2 is 3 5 an end view of the same. Fig. 3 is a perspective view ofmyimproved nut with its threaded and unthreaded members separated toexhibit their cam faces. Fig. 4 is a plan view illustrating theconstruction of the cam faces. The principal feature of my inventionconslsts of the arrangement of the ofisets of cam faces with relation tothe bolt hole of the nut, whereby the operation of the force exerted toscrew the nut home upon the bolt tends to 5 dr1ve the unthreaded memberor washer to ward and around the bolt and not outward and away from thebolt as'heretofore, thereby avoiding the danger of splitting theunthreaded member or washer, even when made of very thin metal.

In the drawings A indicates the threaded Serial No. 424,360. (No model.)

member of my improved nut, which threaded member is provided with theinclined cam face 0 which is arranged inclined away from the directionof rotation of the nut when such nut is screwed upon the bolt.

B indicates the washer or unthreaded member, the cam face 0' of which isinclined in the direction of rotation of the nut while being screwedupon the bolt, and is complementary to the inclined face 0 of the nut A.The inclined face 0 of the unthreaded member or washer B terminates atits end in an offset e which has its face arranged tangential to thebolt hole D of such member while the offset 6 at the end of the face 0of the nut Ais complementary to the offset e.

P represents the bolt plate against which the nut is screwed.

In practice the unthreaded member 13 is placed upon the bolt G and'thethreaded member A, which is provided with screw threads If is screwedupon the bolt as shown in Fig. 1. The several facets of the cam faces,which facets are indicated by a a a and b b b, and the ofisets e and eare complementary to each other; and the oifsets e of the threadedmember A engage with the oifsets e of the unthreaded member B and suchunthreaded member is thereby forced to turn on the bolt as the threadedmember is tightly screwed home thereupon. I do not claim the combinationof a threaded and unthreaded member provided with cam faces andcomplementary offsets to be broadly new. By arranging the ofisets e asshown tangential with the bolt hole D the pressure upon such offsets ofthe washer is thus brought to operate to compress a portion of thewasher toward or against the bolt thus to drive the washer around thebolt without any liability of splitting from undue outward strain. Thiswill be fully understood by referring to Fig. 4.

The unthreaded member 13 is smooth upon its under side, and theperimeters f of the unthreaded member, and of the threaded member areequal and correspond in shape so that a wrench may be appliedsimultaneously to both the unthreaded and threaded members when the nutis screwed home upon the bolt and it may also be applied to both memberswhen it is desired to remove the nut from the bolt. If the threadedmember starts to unscrew from the bolt the cam faces a and b engage andjam the nut upon the unthreaded member in the ordinary manner oflock-nuts of this class.

I am aware that it is old to provide a nut and a washer with cam facetsand I am also aware that it is old to provide a washer with cuttingedges arranged tangential to the bolt hole and presented toward ,thedirection of rotation of the nut while being screwed upon the bolt, sothat when the nut is screwed home upon the bolts such tangential edgeswill bite into the base of the nut to prevent it being unscrewedtherefrom, but such construction possesses the defect of bringing thestrain upon the washer in a direction which is outward from the boltwhen force is applied to unscrew and the washer is liable to be split bysuch pressure, thus preventing its use a second time. The essentialpoint of difference between my invention and the former construction isthat in my device the ofisets upon the washer are arranged to bring thestrain upon the washer in such a manner as to operate to compress thewasher upon the bolt and to drive it around the bolt, and although thebase of mysaid washer is smooth,

the nut can be tightened so forcibly that it will not become loosenedaccidentally, and yet a wrench may be applied to both the washer and nutsimultaneously and they may be removed in the ordinary way from the boltwithout being in any manner injured, so that they may be usedrepeatedly.

Now, having described my invention,what I claim as new, and desire tosecure by Letters Patent, is-

The nut comprising the unthreaded member provided with the cam facetsinclined in the direction of rotation of the nut while being screwedupon the bolt, such facets each terminating at its end in an ofi'setwhich has its face arranged tangential to the bolt hole, and thethreaded member provided with the cam facets and offsets arrangedcomplemeutary to the facets and ofisets of the unthreaded member,whereby the unthreaded memberis prevented from splitting while the nutis being screwed home upon the bolt; substantially as and for thepurpose set forth.

A. A. BROWN.

Witnesses:

JAMES R. TOWNSEND, ALFRED I. TOWNSEND.

